The continuing development and use of polymorphic DNA markers has become an increasingly effective means of identifying genetic traits or individuals. Improvements in speed and sensitivity of this technology have produced growing commercial opportunities for applications in linkage analysis, disease detection, forensic sciences, and paternity determination during the past decade. However, current methods are still relatively timeconsuming and often work best in conjunction with the use of radioactivity. Our Phase I application proposed the development of a new and superior class of amplifiable polymorphic markers based on a proprietary concept. In meeting or exceeding all of the goals of our Phase I proposal, we demonstrated a reasonable frequency and degree of polymorphism for these new markers, and that they can be detected more quickly, cheaply, and simply in non-isotopic formats than previously developed markers. The Phase II application proposes the isolation of a large number of these markers for general use in linkage mapping and disease detection. The most polymorphic of the markers will be tested in several different racial/ethnic populations to develop highly discriminating multiplex sets for applications in forensic sciences, paternity determination, monitoring of bone marrow transplants, and tissue culture cell identification. PROPOSED COMMERCIAL APPLICATION: The superior ease of use, cheaper cost, and quick handling of ITR markers will allow their rapid commercialization as multiplex systems for forensic analyses, generation of convicted offender databases, tissue culture identification, monitoring of bone marrow transplantation, and paternity determinations. Fifty to 200 new markers of this superior quality will also be available for linkage studies.